In a high speed wrapping and packaging machine such as a horizontal wrapping machine, a continuous film of packaging material is supplied from a roll and drawn past a film former which shapes the film into a continuous tube of packaging material. Products to be wrapped are supplied through the film former and into the tube of packaging material such that products are spaced apart from one another in the packaging material tube. The packaging material tube is then cut and sealed as each product, carried within the tube, passes a sealing and cutting station. In this way, an individual sealed package is produced for each product from the continuous roll of packaging film material.
As the enclosed tube of packaging film material, carrying products spaced apart from one another, advances through the sealing and cutting station, a pair of opposed cutting heads are rotated into engagement with the packaging film tube at a location on the film tube between each successive pair of products. The cutting heads typically carry a crimper arrangement of cutting blade on one cutting head shaft extending transversely to the packaging film tube and an anvil on the other cutting head shaft which cooperates with the cutting blade for performing the cutting operation. Alternative cutting shaft embodiments have two blades or anvils spaced 180 degrees apart on the shaft or four blades or anvils spaced 90 degrees apart on the shaft. Operators typically use two different head configurations for their various wrapping and cutting operations. This requires the operator to periodically remove the cutting head shafts with one crimper configuration and replacing them with shafts having a different crimper configuration.
The cutting/crimper shafts on high speed horizontal wrapping and packaging apparatuses typically do not rotate at a constant angular velocity. As the crimpers come together on the film they must slow down to match the speed of the film passing between the crimpers. Crimpers generally need to slow down more for shorter products than for longer products. An epicycle drive is used to create the nonuniform rotational speed of the shaft. In a typical epicycle drive, a crankshaft is positionable so as to be concentric or non-concentric with the input shaft. When the crankshaft is moved to a non-concentric position, it has a nonuniform rotational speed. A cam arrangement is used to couple the input shaft and crankshaft to one angle and thereby enables the nonuniform speed of rotation of the crankshaft.
A delay or deceleration profile, hereinafter termed a "pause " must be adjusted each time a different crimper arrangement is used and each time a different length of product is packaged. Adjusting an epicycle drive to match the product to be wrapped is a time consuming task which requires changing belts, pulleys, sprockets and related items. Therefore, it is an object of the present invention to provide a cutting head drive apparatus which allows easy adjustment of the pause when a different crimper arrangement on the shafts is used or a different length product is being wrapped and packaged.
Yet another object of the present invention is to provide a cutting head drive apparatus which incorporates a dual drive allowing the operator to interchange cutting shafts having different crimper head configurations without the need for changing belts, pulleys and related items on the drive apparatus.
Still another object of the present invention is to provide a cutting head epicycle drive arrangement which allows changing over to a different cutting head configuration and being able to adjust the epicycle drive for obtaining the proper pause without changing sprockets, chains and related items.
A further object of the present invention is to provide a epicycle drive arrangement in which the power is selectively transmitted from the crankshaft to the output shaft through one of two timing pulley and clutch arrangements.
Another object of the present arrangement is to provide an epicycle drive arrangement which incorporates two drives independently controlled by air clutches which allows the operator to change from one crimper configuration to another and provide the proper drive and pause requirement by disengaging one clutch and engaging the other clutch.
A still further object of the present invention is to provide a dual drive arrangement which allows the pause to be adjusted by utilizing a pivoting epicycle rack to change the distance between the axis of rotation of the crankshaft and the output shaft selectively coupled to two clutch arrangements.